<!DOCTYPE html>
<html>
  <head>
    <title>munderover@accent</title>
    <meta charset="utf-8"/>
  </head>
  <body>
    <math>
      <munderover accent="true"><mtext>X</mtext><mo>O</mo><mo>O</mo></munderover>
    </math>
  </body>
</html>
